Alan Shatter, a veteran within the senior coalition partner Fine Gael, has stood down just weeks after the Garda chief Martin Callinan stunned the country with his resignation amid a storm of controversies involving his force.

Mr Shatter, who also serves as Defence Minister, told Taoiseach Enda Kenny he was offering to stand down after reading a government-ordered report into the handling of whistleblower allegations of widespread Garda wrongdoing and malpractice.

A dossier by serving Sergeant Maurice McCabe has rocked the force.

In a bid to calm growing tensions over a series of scandals, the government asked a senior criminal barrister to examine ten sample cases - including alleged murder, abduction and assault - which Sgt McCabe claims were not properly investigated.

The 300-page report is to be published on Friday but was handed to both Mr Kenny and Mr Shatter last night.

Announcing the resignation in the Dail, Mr Kenny said the report found Mr Shatter to be "inadequate" in his obligation to be independent in his investigation of the whistleblower allegations.

"The Minister having read the report and considered its implications has sent me his resignation which I have accepted with regret," he said.

Mr Kenny said he did not demand Mr Shatter's resignation and added that he was not expecting anyone else to stand down over the controversy.

The Government will now set up a full statutory inquiry - known as a Commission of Investigation - into the corruption allegations.

In a resignation letter, Mr Shatter said he had reservations about the report but was offering to stand aside in the interests of his party and the junior coalition partner Labour Party ahead of upcoming elections.

"I am anxious that any controversy that may arise on publication of the report does not distract from the important work of the Government or create any difficulties for the Fine Gael or Labour parties in the period leading in the European and local government elections," he wrote.

"It is my judgement that the only way in which such controversy can be avoided is by my offering you my resignation."

However, Mr Shatter said he had only read three chapters of the report and agreed there should be a statutory inquiry.

It is the latest in a wave of top-level investigations into alleged Garda wrongdoing.

Six weeks ago, then Garda Commissioner Martin Callinan shocked even his closest colleagues when he resigned over the uncovering of a secret system recording telephone calls at police stations for decades.

A Supreme Court judge is heading up a State inquiry into the impact of the taped conversations - specifically on the investigation into the murder of French film producer Sophie Toscan du Plantier.

A legal action by former English journalist Ian Bailey for wrongful arrest in the investigation in west Cork exposed the recording system.

A retired High Court judge is leading another independent investigation into the alleged bugging of the Dublin headquarters of the force's official watchdog, the Garda Siochana Ombudsman Commission.

Mr Shatter had previously shrugged off allegations of an unhealthily close relationship with Mr Callinan.

Cabinet colleagues stood by him yesterday when it was revealed that he had breached data protection laws in revealing on live television last year that a political opponent, Mick Wallace, had been seen by police using his mobile phone while driving, although he was not prosecuted.

Tanaiste and Labour Party leader Eamon Gilmore said Mr Shatter's resignation was inevitable.

"He has had many accomplishments during his time in office, including reform of the legal profession, modernisation of the courts, landmark personal insolvency legislation and modernisation and reform of the prison service," he added.

"He was Minister for Justice in difficult economic times and he has a record of which he should be proud."

Several political allies and opponents have praised Mr Shatter - reputed to be at his desk by 6am every morning - for his record as a reforming and hard-working government minister.

But Clare Daly - one of a small number of independent TDs who have been a force in exposing claims of Garda malpractice - attacked the Government for standing by him.

"It's not the time you get out of bed at that's important, it's what you do with that time," she said.

"While not bearing any personal grudge against Mr Shatter, I would say that everybody on this side of the house is only amazed that it has taken this long.

"In other jurisdictions he would have been long gone."

Sinn Fein leader Gerry Adams said Mr Shatter had defamed the Garda whistleblowers, misled Parliament and actively sought to make little of concerns over the alleged bugging of the Garda watchdog's headquarters.

But he added: "Mr Shatter is not the only one who is culpable - that will become clear and people will remember how (the Taoiseach) and Labour stood by, reinforced rubbished, dismissed genuine efforts to sort these matters out."